As the number of network providers converting their existing networks from the use of traditional electrical (i.e., copper) cables to optical fiber increases, owners and operators of local access networks (LANs) are updating the equipment on their local networks to take advantage of the benefits of optical fiber and to assure the ability to connect to the network providers' networks. As a result, owners and operators of the LANs are being forced to upgrade their current equipment, requiring major investments of time and money.
FIG. 1 illustrates a prior art traditional local access network (LAN) 180 comprised of traditional electrical cabling. The traditional LAN 180 is constructed using Ethernet technology, which defines standardized signaling and networking protocols to allow devices on the traditional LAN to communicate (i.e., transmit and receive packets of data). As shown in FIG. 1, the traditional LAN 180 is separated into discrete parts across a number of locations such as a data center 110, a campus/buildings 120, floors/closets 130, and access location 140. Although FIG. 1 shows these locations as separate places, the locations may be the same place. For example, the data center 110 may be in a closet of a building 130 on a campus.
The traditional LAN 180 communicates with an external network, such as the internet, a wide area network, etc., through a switch and/or router 101 connected to the external network (not shown). In this regard, all incoming and outgoing communication between the external network and the traditional LAN passes through the switch and/or router 101. The switch and/or router 101 communicates with one or more data center switches 102 in the data center 110, or elsewhere. The data center switches 102 control and arrange the transmission of data to and from smaller subsets of the traditional LAN 180, such as subsets of the LAN arranged in particular buildings or locations on a campus. In this regard, communication of data over each smaller subset of the traditional LAN 180 may be controlled and directed by a subset switch, such as subset switch 103. The one or more subset switches 103 in turn communicate with respective local switches 104, to which end user devices 105, such as personal computers are connected. Data may be transmitted within the traditional LAN 180 without being routed through the switch and/or router 101. In other words, data may be transmitted between end user devices 105 and the various switches and router of the traditional LAN 180 without traversing an external network.
Each switch, router, and other component of the traditional LAN 180 may require electrical power, as well as sufficient cooling. The number of switches and routers may be large, depending on the size of the traditional LAN 180, in some cases numbering in the thousands or tens of thousands. As such, the cost to own and operate the traditional LAN 180 involves significant continued expenditures in energy and money to maintain and power the components of the traditional LAN, as well as to provide the necessary cooling for the components to operate.
Communication between the servers, switches, etc., on the traditional LAN 180 occurs over wired connections 131, as further shown in FIG. 1. Such connections are typically copper wire connections, or in some instances, multi-mode fiber (MMF) connections. The copper wire and MMF wire runs are limited to a range of around 100 meters and 550 meters, respectively. Longer runs of wire may be possible, although such runs would require the use of additional components, such as repeaters and boosters which require further expense and power usage. Additionally, multiple runs of wire are needed to provide enough bandwidth within the traditional LAN 180. As such, a large amount of physical space may be required to house the wiring and components of the traditional LAN 180.
Many traditional LANs are being upgraded to passive optical local area networks (POLs). FIG. 2 illustrates a prior art passive optical local area network (POL) 190 constructed of fiber-optic cabling. The POL 190 is constructed in accordance with standardized signaling and networking protocols, such as those developed by the ITU and IEEE, to allow devices on the POL to communicate. As shown in FIG. 2, the POL 190 is separated into discrete parts across a number of locations such as a data center 110, a campus/buildings 120, floors/closets 130, and access location 140. As with the traditional LAN shown in FIG. 1, these locations are shown as separate places, although the locations may be the same place.
The passive optical local network 190 communicates with an external network, such as the internet, a wide area network, etc., through a switch and/or router 101 connected to the external network (not shown). The switch and/or router 101 communicates with an optical line terminal (OLT) in the data center 110, or elsewhere. The OLT controls and arranges the transmission of data to and from one or more optical network terminals (ONTs), or sometimes referred to as optical network units (ONUs), such as optical network terminal 153, located in one or more access locations 140. The ONTs 153 may convert the fiber-optic signals from the OLT into electrical signals and electrical signals from end user devices, such as end user devices 105, into fiber-optic signals. In this regard, end user devices 105 may communicate on the POL 190 through electrical connections with the one or more ONTs.
The signals from the OLT to the ONTs, and vice versa, are transmitted over an optical distribution network (ODN). The ODN may include single mode fiber (SMF) 154 and passive optical splitter 152. Single mode fiber 154 may have a range (i.e., length) of about eighteen miles, or more or less, without the need for signal boosters or repeaters. The range of the SMF 154 is about 300× greater than that of copper wire and MMF wire runs. Moreover, based on the standard implemented by the POL 190, bandwidth may be greater than that offered by a traditional LAN 180. For instance, the POL 190 may operate within defined data rates as shown in table 1, below:
TABLE 1StandardUpstreamDownstream10GEPON10Gbit/s10Gbit/sGPON1.25Gbit/s2.5Gbit/sEPON1Gbit/s1Gbit/sNGPON24 × 10G Gbit/s4 × 10G Gbit/sXG-PON2.5Gbit/s10Gbit/sXGS-PON10Gbit/s10Gbit/s
The passive optical splitter 152 may split the data signals received from the OLT 150 into 64 signals, or more or less. Each split signal may contain the same data as the data signal received from the OLT 150 and each split signal may be sent to a respective ONT 153. Conversely, the passive optical splitter may combine up to 64 signals, or more or less, received from ONTs onto a single SMF. Additionally, the passive optical splitter 152 may operate without the need for a power source (i.e., passively).
The data transmitted from the OLT 150 to user devices may be broadcast to all ONTs on the POL 190. The data may be encrypted in accordance with the network standards. In this regard, the data, although received by every ONT 153, may be readable only by the ONT 153 for which the data was directed. Further, since each respective ONT 153 receives the same signals from the OLT only a single SMF 154 is required to send data to up to 64 ONTs, or more or less.
As such, the POL 190 is configured as a high capacity, point-to-multipoint network, which allows for high user density over a single SMF 154. Thus, the number of cables required to create a POL is, in some instances, significantly less that than needed in a traditional LAN. Further, the POL 190 offers improvements over a traditional LAN 180, such as increased bandwidth while reducing the amount wiring, switches, and other components needed to operate the LAN. Further, the POL 190 requires less power to operate and cool the components, as the number of switches, routers, and other such hardware is thereby leading to decreased cost to operate and run in comparison to a traditional LAN.
One or more network managers may manage the components of the traditional LAN 180 and POL 190 from one or more of the locations through one or more servers, such as server 160, connected to the various switches and/or routers. In this regard, the network managers may program the server to assign bandwidth to certain user devices/switches/routers. Moreover, the server 160 may provide services, such as firewalls, IPTV, DHCP servers, mail servers, etc., to the LANs.
Servers, such as server 160 in the POL 190, may run a management suite of programs. The management suite of programs may allow the server 160 to control the operation of the OLT 150 through a client suite of programs executing on the OLT 150. In this regard, the management suite of programs may control the flow of data through the OLT 150, such as by controlling network traffic of certain types or from particular locations. The management and client suites often require significant time investments by network managers to learn how to program and operate the suites of programs. Further, in order for updates to the client suite of programs on the OLT 150 to occur, the POL 190 typically needs to be shut down and reset to provide the server 160 time to update OLT 150, and for the OLT 150 to update and reset. Likewise, versioning (i.e., assuring compatibility between the versions of the management and client suite of programs,) needs to be maintained, requiring further downtown of the POL 190 when suite updates are needed. Moreover, the cost of the OLT 150 may be significant, often costing tens of thousands of dollars or more. As such, significant costs and time requirements often deter owners and operators of LANs from implementing a POL.